<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <input type="text" value="Mozilla">
  <button onclick="selectText()">点我</button>

</body>
<script>

  function selectText() {
    const input = document.querySelector("input")
    // input.focus();
    // input.setSelectionRange(2, 5);
    input.setSelectionRange(-1, -1);
  }
</script>

</html>